News & Opinion

A German study published in The Annals of Thoracic Surgery suggests that surgical removal of breast cancer metastases that affect a small part of the lungs may help women live longer.

In their study, the researchers also examined factors such as size, subtype and the number of metastases, which may influence overall survival, the time a person lives from the beginning of a study until death from any cause.

Background and Reason for the Analysis

Experts estimate that nearly 30 percent of women with early-stage disease will later develop metastatic breast cancer, when the cancer cells spread to distant parts of the body, such as the bones, liver, lungs and brain. The average life expectancy of a woman with metastatic disease can vary widely depending on a large number of tumor and treatment factors.

Surgery is rarely performed on women with metastatic breast cancer, including those with lung metastases, since to date no prospective, randomized trial evidence has proved it beneficial. Prospective cohort studies follow treatment arms (or groups of participants) over time to determine how different treatments (e.g., surgical removal vs. no surgical removal of metastases) or factors under study correspond to long-term health outcomes (e.g., overall survival). Randomized controlled trials are studies in which neither the researcher nor the participant knows to which treatment arm she was assigned, eliminating bias in interpretation of the results.

The researchers’ goals were to learn if removing metastases from the lungs by surgery offers a survival benefit to women with metastatic breast cancer affecting small parts of the lungs. They also wanted to find out what other factors might influence survival rates.

Study Structure

The study’s investigators enrolled 81 women with lung metastases from April 1982 to May 2007. The researchers followed up with the women by mail or telephone or accessed information about them through outpatient records after their surgeries.

The study’s investigators collected data from the women’s medical records to determine the estrogen-, progesterone- and HER2-receptor status of the tumors. Of the 81 participants, 53 women had receptor status recorded in their records.

Findings

Researchers reported that 71 of the women were operated on only once, nine women underwent surgery twice and one woman had three surgeries. The median overall survival of all participants after the lung metastases were surgically removed was 82.4 months (almost 7 years).

Of the 81 women who had surgery for metastatic breast cancer of the lung,

six women (or 7.4percent) had some tumor cells still visible via microscope and a survival rate of 23.6 months (an estimated 2 years)

nine women (11 percent) had cancers that were visible to the naked eye, and a survival rate of 20.2 months (a little under 2 years)

Investigators found that survival improved significantly if the cancer was ER- and/or PR- positive.

The number and size of metastases were also factors that influenced survival. Women with a single metastasis lived longer than those who had two or more, and women with metastases smaller than three centimeters survived longer than those with metastases larger than three centimeters.

Seven women in the study also had metastases in the mediastinal (between the lungs) and hilar (the airways of the lungs) lymph nodes. Women with no cancer in their mediastinal or hilar lymph nodes experienced prolonged median survival rates compared with those with who had metastases in these lymph nodes (103.4 months [about 8.6 years] and 32.1 months [about 2.7 years], respectively).

What This Means For You

Prior to the publication of this article, no study examined the impact of surgery on lung metastases. These findings suggest a survival benefit for women whose metastases affecting a small part of the lung are removed by surgery. The authors feel that this benefit can be significant if you have one site of metastasis in your lungs that is less than three centimeters and is HR-positive.

Although this study suggests a survival benefit, it must be noted that this is a small study with 81 participants. Typically, research studies have hundreds or thousands of participants to ensure that the results are applicable broadly of the population treated. Additionally, since the study did not randomly assign the women to “treatment” or “no treatment,” those who were selected for surgery may have had selection bias, meaning that those chosen for and who elected to enroll in the trial may have done so because they had better outcomes to begin with, slanting the results towards better outcomes in those having the surgery.

If the metastatic disease in your lungs matches these criteria, talk with your doctor to see whether surgery might benefit you.

Even if the metastatic breast cancer you have does not match these qualities, there may still be other treatment options that are available to you. Talk to your healthcare team about treatment options that work best for you.